By-pass valve for locomotive-engines.



r.. G. MANCHESTER z S.. S. 1vf` .G-PL.- YuPASS VALVE E'OR LGGOMOTIVE ENGINES.

APPLIGATIQH FILED AUG. 21, 191.22.

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H. C. MANCHESTER L S. S, RIBGEL. BY-PASS VALVE FOR LOCOMOTIVE ENGINES. APPLIcls-LTIoN MLED AUG. 21, 1913.

1,089,570, V Patented Mar. 10, im.

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B3n-PASS VALVE FOB LQGQMOTWE ENGINES.

APPLICATION FILED AUG.21. i913.

Patented Mar, l0, 1914.

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UNITED STATES PATENT OFFICE.

HENRY C. MANCHESTER AND SAMUEL iS. IRIEGEL, OF SCRANTON, PENNSYLVANIA.

:BY-PASS VALVE FOR LOCOMOTIVE-ENGINES.

Specification of Letters Patent.

Patented Mal. 10, 1914.

Application led August 21, 1913. Serial No. 785,889.

-a certain new and useful Improvement in By-Pass Valves for Locomotive-Engines, of which improvement the following is a speciication.

This invention, relates to locomotive en.-

gines, and has for its principal object to provide an improved valve mechanism for automatically opening communication through a ,by-pass between the opposite ends of the engine cylinder when the locomotive is drifting, or v'running with Vthe throttle closed, thereby permitting free passage of the contents of the cylinder from one end to the other, and Vmaintaining the piston substantially balanced as topressure upon its opposite sides in all positions.

Another feat-ure of our improvement consists in means for admitting a limited quantity of steam attlie Sametime that the bypass is open, andthereby prevent the formation of a vacuum in thecylinder, assist in the lubrication, eliminate the carbonization l ably employ a valve of the differential holof ,oil and prevent the chilling of the cylinder walls by the indraft of cold air.

. Our improvement Ais particularly useful for engines operating with superheated steam, in which the parts are maintained at high temperatures, but it is also applicable in connection with engines using saturated steam.

In the practice of our invention we preferlow piston type, subject to the opposing pressures of the engine valve steam chest, and the live steam from tll'e boiler, whereby, when the throttle is open, the high pressure from the steam chestl operates to hold the by-pass closed, but when the throttle is closed and the pressure from the steam chest falls, the opposing boiler pressure operates to open the ley-pass and to admit a limited quantity of `live steam into the cylinders.

In the accompanying drawings: Figure 1 is a vertical section .through a locomotive engine cylinder and steam chest, showing inl section one form of' our improved valve mechanism applied thereto; Fig. 2, a central sect-ion, on a larger scale, of one ofthe improved valve mechanisms; Fig. 3, a t-ransverse l'section taken on the line 3-3 of Fig.

23E-ig. 4,- anend elevation ofthe valve castail view showing a slightly modied forni-'64;

of valve.

According to the construction shown in the drawings, our improvement is illustrated in connection with a locomotive engine having a cylinder, 7, a steam chest, 8, 35

adapted for a steam distribution valve of the piston type, and induction and eduction ports, 9, leading from the steam chest to the opposite ends of the cylinder. The by-pass,

21, establishes communication between the 7g opposite induction ports and, when open, affords a free passage from one end of the cylinder to the other. Theby-pass valves, 10, two bein shown in this instance, are

mounted in c ambers, 11, each communicating ywith an induction and eduction port, 9, leading to the cylinder, and each valve may be in the form of a differential hollow piston closed at the valve end and having an intermediate piston portion, 10a, fitting the 80 bore of the middle part of the valve casing, 12, and a larger piston portion, 10", fitting an enlarged outer chamber, 12, which is closed by the cap, 13. For the purpose of assisting inV supporting and guiding the 35 valve in its movement, the cap is provided with a central plunger-like projection, 133,' extending'within the hollow piston valve. This makes a very light construction, and

the chamber, 14, thus formed within the In piston valve, serves as a dash pot for cushioning the action of the valve. A small port, 15, may be drilled through the wall ofthe valve from the valve chamber into the dash pot, 14|, for slowly relieving the( 95 pressure therein. An adjustable screw stem, 16, may be mounted in the cap, 13, and extend through the same to a position to limit the opening movement of the valve,

or Ait may be screwed down to hold the valve by means of pipe, 18, while live Vsteam pressure from the boiler is admitted through pipe, 19, to the lannular chamber, 17, be-

tween the diierential heads,`10a and l0", of the hollow piston valve. Grooves, 20, are

formed longitudinally in the bore of the fait valve` casinggto serve as ports for opening communipatioilroundthepiston head, 10,

when the valve moves toits open position, and thereby admit av limited quantity of steam into the valve chamber, by-pass and engine cylinder. Packing rings may be mounted on the differential lpiston portions for preventing leakage around vthe same.

When the locomotive is running with the throttle o`en, the steam admitted through the thrott e to the steam chest also passes through pipe, 18, into chamber, 12a, and acting on the large annular area of piston head, 10b, holds the valve, 10, upon its seat with the by-pass closed. The live steam pressure from the' boiler admitted through pipe, 19, to the annular chamber, 1j, acts upon the differential piston in the opposite direction to the pressure in chamber, 12a, but overa smaller effective area, and thereforeis insuicient to move the iston to open the valve. When the thrott eis closed and the lo'comotive continues running, or drifting, r'the pressure'V in the steam chest, and consequently inv chamber, 12a, falls rapidly, and

as soonv as the opposing bollerV pressure in' chamber, 17, acting on the smaller effective area of piston, 10b, overcomes the diminishing pressure in chamber, 12, the differential piston moves the valve away from its seat and opens the by-pass between the opposite ends of the cylinder. ,As the piston continues to ymove outward, the head, 10a, reaches a position in which the grooves, 20, open communication around said piston head, and therebya'dmt a limited quantity of steam into the valve chamber, by-pass and through the ports into both ends of the cylinder. The engine piston isvthus balanced as to fluid pressure upon its opposite sides, and the contents of the cylinder pass freely from one end to the other, through the by-pass,as the piston reciprocates. The small amount of live steam admitted serves to prevent a vacuum being formed in the cylinder by the pumping'action of the piston, and maintains the temperature of the cylinder Walls, which is very important, particularly Where superheated steam is employed. It also serves to lubricate'the cylinder, and prevents the carbonization of the oil. When the throttle is again opened, the steam pressure from the steam chest admitted to chamber, 12a, acts upon the larger area of the piston head, 10b, and, overcoming the boiler pressure in chamber, 17, moves the piston' andi valve to cutolf the grooves, 20, and close 4the by-pass. The differential piston is supported and guided in its movement upon the long cylindrical bearing of the projection, 13a, Within the hollow piston, and the chamber, 14, serves as a dash pot to cushion the action of the valve in opening and closing. By means of this construction, the valve may be made very light and durable, and injury to the parts by excessive hammering of the valve Will be avoided.

made structurally separate. therefrom, and

connected to said piston in any suitable or preferred manner. As shown in Fig. G, the

valve, 10, is, formed separate and connected to the dilerential piston by a stem, 10d. It

is also provided with a curved joint connection, 10E, by means of which the valve is adjustably mounted so as to compensate for any slight difference in the alinement of the valve and its seat, and insure the positive closure of the valve. l

Ve claim as our invention and vdesire t-o secure by Letters Patent:

1. In a locomotive engine, the combination vvith the cylinder, steam chest, and a bypassconnecting the opposite ends of the cylinder, of a. valvev for controlling said bypass, and means governed by the opposing pressures of the steam chest and the boiler for operating said valve. A

` 2. In a locomotive engine, the combination with the cylinder, steam chest, and a bypass connecting the opposite ends of the cylinder, of a valve for controlling said bypass, and a movable abutment subject in one directionvto pressure from vthe steam chest tending to close said valve, and inthe opposite direction to pressure from the boiler tending to open said valve. I

3. In a locomotive engine, the combination with the cylinder, steam chest, and a bythe boiler for operating said valve, and

means also controlled by said abutment for admitting a limited quantity of steam into the cylinder when said valve is open.

4. In a locomotive engine, the combination with the steam chest, the cylinder having induction ports at its opposite ends, and a' by-pass connecting said ports, of valves for controlling communication between said ports and by-pass, and diiferential piston means subject toit-he steam' chest pressure on one side and to the boiler pressure on the other side for operating said valves. Y

5. In a locomotive engine, the lcombinationvvith the steam chest, cylinder, and bypass, of a by-pass valve mechanism comprising a casingcontaining a chamber communieating with said by-pass, and a diEerent-ial piston valve mounted in said chamber and 'operated by the opposing pressuresfrom the eating with said by-pass, and a di'erential piston valve mounted in saidchamber and operated by the opposing pressures from the st-eam chest and from the boiler to control said ley-pass and the admission of a limited quantity of steam into the cylinder.

7. ln a locomotive engine, the combination with the steam chest, cylinder, and bypass, of a by-pass valve mechanism comprising a casing containing a chamber communieating With said bypass, a dierential piston valve mounted in said chamber, having a hollow body and subject in one direction to pressure from t-he steam chest, and a xed guide extending Within the hollow body of the piston valve and forming a support therefor and a dash pot closure therein.

8. In a` locomotive engine, the combination with the steam chest, and cylinder having a by-pass connecting the opposite ends thereof, of a valve controlling said by-pass and having a differential piston subject to the opposing pressures of the steam chest and the boiler, and a casing having passages controlled by the movement of said differential piston for admitting a limited quan tity of live steam to the cylinder.

9. In a locomotive engine, the combination 'With the steam chest, and cylinder havcylinder, of a hollow piston valve subject to 40 iuid pressure for controlling said by-pass, a guideprojecting Within the hollow piston, and an adjustable stem extending through said .guide for limiting the travel of said valve.

HENRY C. MANCHESTER. SAMUEL S. RIEGEL. Witnesses:

FRANK J. SCHRAMM, H. A. CARPENTER.

Copies of this patent may be obtained for flvs cents each, by addressing the Commissioner of Infants.

Washington, ID. C. i 

